ترغب بنشر مسار تعليمي؟ اضغط هنا

Determination of $overline{m}_b/overline{m}_c$ and $overline{m}_b$ from $n_f=4$ lattice QCD$+$QED

93   0   0.0 ( 0 )
 نشر من قبل G. Peter Lepage
 تاريخ النشر 2021
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

We extend HPQCDs earlier $n_f=4$ lattice-QCD analysis of the ratio of $overline{mathrm{MSB}}$ masses of the $b$ and $c$ quark to include results from finer lattices (down to 0.03fm) and a new calculation of QED contributions to the mass ratio. We find that $overline{m}_b(mu)/overline{m}_c(mu)=4.586(12)$ at renormalization scale $mu=3$,GeV. This result is nonperturbative. Combining it with HPQCDs recent lattice QCD$+$QED determination of $overline{m}_c(3mathrm{GeV})$ gives a new value for the $b$-quark mass: $overline{m}_b(3mathrm{GeV}) = 4.513(26)$GeV. The $b$-mass corresponds to $overline{m}_b(overline{m}_b, n_f=5) = 4.202(21)$GeV. These results are the first based on simulations that include QED.



قيم البحث

اقرأ أيضاً

We prove that the moduli spaces of curves of genus 22 and 23 are of general type. To do this, we calculate certain virtual divisor classes of small slope associated to linear series of rank 6 with quadric relations. We then develop new tropical metho ds for studying linear series and independence of quadrics and show that these virtual classes are represented by effective divisors.
We provide a new geometric interpretation of the multidegrees of the (iterated) Kapranov embedding $Phi_n:overline{M}_{0,n+3}hookrightarrow mathbb{P}^1times mathbb{P}^2times cdots times mathbb{P}^n$, where $overline{M}_{0,n+3}$ is the moduli space of stable genus $0$ curves with $n+3$ marked points. We enumerate the multidegrees by disjoint sets of boundary points of $overline{M}_{0,n+3}$ via a combinatorial algorithm on trivalent trees that we call a lazy tournament. These sets are compatible with the forgetting maps used to derive the recursion for the multidegrees proven in 2020 by Gillespie, Cavalieri, and Monin. The lazy tournament points are easily seen to total $(2n-1)!!=(2n-1)cdot (2n-3) cdots 5 cdot 3 cdot 1$, giving a natural proof of the fact that the total degree of $Phi_n$ is the odd double factorial. This fact was first proven using an insertion algorithm on certain parking functions, and we additionally give a bijection to those parking functions.
While lattice QCD allows for reliable results at small momentum transfers (large quark separations), perturbative QCD is restricted to large momentum transfers (small quark separations). The latter is determined up to a reference momentum scale $Lamb da$, which is to be provided from outside, e.g. from experiment or lattice QCD simulations. In this article, we extract $Lambda_{overline{textrm{MS}}}$ for QCD with $n_f=2$ dynamical quark flavors by matching the perturbative static quark-antiquark potential in momentum space to lattice results in the intermediate momentum regime, where both approaches are expected to be applicable. In a second step, we combine the lattice and the perturbative results to provide a complete analytic parameterization of the static quark-antiquark potential in position space up to the string breaking scale. As an exemplary phenomenological application of our all-distances potential we compute the bottomonium spectrum in the static limit.
104 - Zhiyuan Wang , Jian Zhou 2021
In this work we study the tau-function $Z^{1D}$ of the KP hierarchy specified by the topological 1D gravity. As an application, we present two types of algorithms to compute the orbifold Euler characteristics of $overline{mathcal M}_{g,n}$. The first is to use (fat or thin) topological recursion formulas emerging from the Virasoro constraints for $Z^{1D}$; and the second is to use a formula for the connected $n$-point functions of a KP tau-function in terms of its affine coordinates on the Sato Grassmannian. This is a sequel to an earlier work.
We study smoothing of pencils of curves on surfaces with normal crossings. As a consequence we show that the canonical divisor of $overline{mathcal{M}}_{g,n}$ is not pseudo-effective in some range, implying that $overline{mathcal{M}}_{12,6},overline{ mathcal{M}}_{12,7},overline{mathcal{M}}_{13,4}$ and $overline{mathcal{M}}_{14,3}$ are uniruled. We provide upper bounds for the Kodaira dimension of $overline{mathcal{M}}_{12,8}$ and $overline{mathcal{M}}_{16}$. We also show that the moduli of $(4g+5)$-pointed hyperelliptic curves $mathcal{H}_{g,4g+5}$ is uniruled. Together with a recent result of Schwarz, this concludes the Kodaira classification for moduli of pointed hyperelliptic curves.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا